Garmin Training Center (.tcx) (gtrnctr)

GPSBabel supports reading and writing of tracks in the .tcx
format used by Garmin Training Center™ (GTC). GTC is the successor
to Garmin's Logbook™ program for their workout units. It is a
free upgrade.

GPSBabel can read GTC v1 and v2 files, and can write v2 files.
v2 files are most likely to have a .tcx extension. v1 files
typically have a .hst or .crs extension, depending on whether they
are in the "history" or "course" format.

There is a fundamental mismatch between this format and most of
what we support. GPSBabel deals in waypoints, tracks, and routes.
While we do record things like heart rate and temperature when we know
it, the fundamentals of Training Center are different. It deals in
concepts like laps and calories, which are rather alien to GPSBabel
and most of the formats we support. As such, while we can describe
the tracks pretty accurately, things like calories and heart zone
tracking are not supported. Some of the auxiliary data, such as
heart rate (not zone), cadence, and bicycling power are supported.

One of the most useful things you can do with this format is to send
.tcx files found on the web or elsewhere to any supported GPS
unit. You will probably want to include the transform (rte=trk)
and simplify filters in this process. For example,